Delay emails sent and received through IMAP

I want to put emails the user receives in a sort of "review status" in my app and let users choose manually if they want them to be let through.

For this I need to filter network traffic to withhold emails receivef with the IMAP protocol from Outlook and send them some time afterward. And to the same for emails being sent.

Would this be possible to do on Outlook on Windows 7/8? Or would I be unable to make Outlook receive the mailing after I filter it out?